One-Step Synthesis of Polylactide-Dextran Grafted Copolymers and Its Controlled Release on Coenzyme A

Abstract

The copolymer of poly(lactide acid)-dextran grafted copolymers (Dex-g-PLA) was synthesized by one-step melting reaction method under microwave irradiation. Compared with two-step reaction method, the copolymerization rate was accelerated under microwave irradiation. The conversion of monomer reached 46 % and graft rate reached 142 % after 15 min under microwave irradiation. The influence of different parameters affecting the synthetic process, namely monomer-to-initiator ratio, reaction time, different concentration of catalyst, reaction time and temperature of solvent were investigated. The final products characterized by infrared spectroscopy, nuclear magnetic resonance and powder X-ray diffraction are proved that it indeed is Dex-g-PLA copolymers. Then Dex-g-PLA microspheres loaded with coenzyme A were prepared by double emulsion method. The drug controlled release experiment in vitro demonstrates that after 21 days, the release rate of Dex-g-PLA coenzyme A microspheres reaches 83 % and after 30 days, the release rate reaches 87 % with the saturated release rate.